This is something of a different usage of references from elsewhere
in
the model though, which I see now is one reason why I was a bit
uncomfortable about it. Elsewhere, if resource A needs resource B, it
has a ref to B. Here we have B referring to A.
but isn't this exactly mirroring what the nature of "overrides" is about -
the resource A with content
being "overridden" is not supposed to know about the B that is modifying it ?
/max